# std::operator==,!=,<,<=>(std::error_code)

From cppreference.com
< cpp‎ | error‎ | error code

Defined in header `<system_error>` |  |
bool operator==( const std::error_code& lhs, const std::error_code& rhs ) noexcept; | (1) | (since C++11)
bool operator!=( const std::error_code& lhs, const std::error_code& rhs ) noexcept; | (2) | (since C++11) (until C++20)
bool operator<( const std::error_code& lhs, const std::error_code& rhs ) noexcept; | (3) | (since C++11) (until C++20)
std::strong_ordering operator<=>( const std::error_code& lhs, const std::error_code& rhs ) noexcept; | (4) | (since C++20)

Compares two error code objects.

1) Compares lhs and rhs for equality.
2) Compares lhs and rhs for equality.
3) Checks whether lhs is less than rhs.
4) Obtains three-way comparison result of lhs and rhs.

The `<`, `<=`, `>`, `>=`, and `!=` operators are synthesized from operator<=> and operator== respectively. | (since C++20)

### Parameters

lhs, rhs | - | error codes to compare

### Return value

1) true if the error category and error value compare equal.
2) true if the error category or error value compare are not equal.
3) true if lhs.category() < rhs.category(). Otherwise, true if lhs.category() == rhs.category() && lhs.value() < rhs.value(). Otherwise, false.
4) lhs.category() <=> rhs.category() if it is not std::strong_ordering::equal. Otherwise, lhs.value() <=> rhs.value().

### See also

category | obtains the error_category for this error_code (public member function)
value | obtains the value of the `error_code` (public member function)
operator==operator!=operator<operator<=> (removed in C++20)(removed in C++20)(C++20) | compares `error_condition`s and `error_code`s (function)

Retrieved from "https://en.cppreference.com/mwiki/index.php?title=cpp/error/error_code/operator_cmp&oldid=156720"